This invention relates generally to a portable apparatus for supporting various objects horizontally above the ground and more particularly to a knock-down sawhorse that can be quickly assembled and disassembled.
Sawhorses are typically used on construction sites as temporary structures to provide a horizontal support surface for holding equipment and materials. For example, the sawhorse holds lumber and sheetrock above the ground so that it can be easily cut. Sawhorses are used as support structures in a wide variety of applications for permanently or temporarily holding articles above the ground or floor. For example, sawhorses are used to hold up displays at conventions or can be used as table legs for a temporary student desk.
Since sawhorses are typically used on a temporary basis at any one location, it is important that they can be quickly disassembled (i.e., knocked down) for easy storage and transport to alternative locations. A standard sawhorse includes a horizontal support member, such as a 2.times.4 inch board, permanently nailed at each end to a pair of legs formed by oppositely inclined boards that extend from the sides of the support member. The assembled sawhorse is ungainly and, since the pieces of the sawhorse are nailed together, it cannot be easily disassembled. Thus, the sawhorse cannot be easily transported, for example, in a car to different locations.
To allow easy transport and storage, various types of knock down support structures have been developed. For example, U.S. Pat. No. 3,035,660 to Leon and U.S. Pat. No. 4,574,917 to Stoddard show knock-down support stands that have legs that extend laterally out from ends of a horizontal support member. However, to sufficiently balance the ends of the support member, each leg is specially cut in a triangular pattern from a wide sheet of wood. The wide pieces of wood used for each leg of the support structure are expensive and take more time to cut than the 3 to 6 inch wide boards commonly used in standard sawhorse legs. In addition, wider pieces of wood are typically thinner and, therefore, cannot support as much weight as a standard sawhorse.
U.S. Pat. No. 4,638,885 to Frederick and U.S. Pat. No. 4,890,693 to O'Brian show knock-down sawhorses that have legs that use standard board sizes. However, the sawhorses in Frederick and O'Brian require additional fasteners to attach the legs to the horizontal support members. Additional fasteners, whether made out of wood or metal, increase manufacturing costs and increase assembly time. In addition, it is easier to misplace or lose pieces of the sawhorse which would prevent it from being properly assembled.
Alternative sawhorse configurations use metal clamps that bite into a horizontal support member. Two oppositely inclining boards are nailed into receiving slots at the bottom end of the clamp to form legs. Each clamp has a spring that is compressed by pressing the two legs together. In the compressed state, the claws separate allowing insertion of the support member. By allowing the spring to decompress, the claws clamp onto opposite sides of the support member and the legs move back into an inclined position. Alternatively, if there is no spring, the clamp is held against opposite sides of the support member by holding the legs out in the inclined position. The legs are held in the inclined position by nailing a board across the two leg members.
The metal claws used for this type of sawhorse are expensive and increase the number of components required to assemble the sawhorse. Since the claws and the claw spring are made of metal, they can also rust to the point where they no longer operate correctly. In addition, it is possible that someone cutting wood on the sawhorse can accidentally run over one of the metal claws destroying a saw blade. Since the legs of the sawhorse are nailed to the metal clamp, it is difficult to completely disassemble the sawhorse into easy transportable components.
Accordingly, a need remains for a simple, low cost sawhorse that can support heavy loads and can be quickly assembled and disassembled.